Dynamic Modeling and Control of Interleaved Flyback Module Integrated Converter for PV Power Applications

Abstract

Module integrated converters (MIC) are grid-interactive inverters with a power rating up to 500W. Compared to traditional centralized inverters, they have the advantage of mitigating PV losses that occur through partial shading or module mismatch. In addition, their parallel configuration prevents the single point of failure, thus improving PV system reliability. This thesis conducts a review of the state of the art in MIC topologies. The interleaved flyback module integrated converter (IFMIC) operating in continuous conduction mode (CCM) is identified as having a strong potential for future development. It shows the advantages of high power density, low voltage and current stresses, and low electromagnetic interference, but demonstrates a difficult control problem compared to the discontinuous conduction mode (DCM) in PV grid-tied applications. This control issue is addressed through a detailed modeling, in-depth dynamic analysis, and a two-step controller design approach for IFMIC systems operating in CCM. A decoupled two-step controller design approach is proposed to simplify the modeling and control synthesis in the IFMIC development. A 200W digitally controlled MIC prototype is constructed for evaluation purposes. The simulation and experimental results verify the effectiveness of the proposed modeling and control approaches.

Date of Award	Jun 2013
Original language	American English
Supervisor	Michael Weidong Xiao (Supervisor)